Seals have been used to isolate fluids at various pressures and temperatures. Such seals have existed for use in packing rings, seal rings, piston rings and gland structures in industrial equipment, such as cylinders, pumps, hydraulics and valves, and in oil field equipment, such as down hole tools and surface equipment, requiring seals, for example, against high pressure and low pressure liquids and gases. Typically, these seals are annular seals.
However, under pressure, such seals may be eroded or destroyed and require back-up rings to prevent extrusion of the seal rings. See, for example, U.S. Pat. No. 4,234,197, issued Nov. 18, 1982, Amancharla, et al, entitled Conduit Sealing System. Such systems, however, are bulky and require additional length. At times they require structures with different materials as back-up rings and require a modules of materials at escalating values, which must be maintained even at high temperatures, which is not possible.
Another illustration of seals, as opposed to back-up rings, used in the prior art is shown in U.S. Pat. No. 4,524,982 to Hertz, issued Jun. 25, 1985 and entitled Seal for Aggressive Environments. Hertz merely discloses elastomer-impregnated windings of asbestos yarn impregnated into an elastomer to illustrate a seal ring as opposed to a back-up ring, a sort of “steel belted radial” of seals. For similar encapsulated rings, see also, U.S. Pat. No. 4,423,544 to Kashmerick, issued Jan. 3, 1984 for A Method of Making Composite Gasket. For back-up rings, see also, U.S. Pat. No. 3,810,639, issued May 14, 1974, to Scanell, entitled Frangible Back-up Ring for Sealing Rings.
It is an object of the current invention to avoid the distortions and other problems of the prior art through the use of a non-homogeneous wire encapsulated anti-extrusion ring.